Subsequent Events (Details) - USD ($) $ / shares in Units, $ in Millions	Jul. 16, 2018	Feb. 14, 2018	Feb. 12, 2018	Jun. 30, 2018	Feb. 11, 2018
Subsidiary, Sale of Stock [Line Items]
Tax savings payable to TRA Holders (as a percent)			85.00%
Tax savings benefit recorded as APIC (as a percent)			15.00%
Follow On Offering | Subsequent event
Subsidiary, Sale of Stock [Line Items]
Common stock, shares outstanding	74,889,772
Increase in number of combined shares outstanding	0
Tax savings payable to TRA Holders (as a percent)	85.00%
Tax savings benefit recorded as APIC (as a percent)	15.00%
Class A Common Stock
Subsidiary, Sale of Stock [Line Items]
Common stock, shares outstanding	37,646,562			26,450,000	0
Class A Common Stock | Subsequent event
Subsidiary, Sale of Stock [Line Items]
Issuance of common stock (shares)	11,196,562
Common stock, shares outstanding	37,646,562
Outstanding shares in class as a percent of the total shares outstanding	50.30%
Class A Common Stock | Follow On Offering
Subsidiary, Sale of Stock [Line Items]
Issuance of common stock (shares)	11,196,562
Share price (in dollars per share)	$ 33.25
Class A Common Stock | Follow On Offering | Subsequent event
Subsidiary, Sale of Stock [Line Items]
Issuance of common stock (shares)	10,000,000
Share price (in dollars per share)	$ 33.25
Net proceeds from issuance of Class A common shares	$ 359.3
Class A Common Stock | Underwriter's option
Subsidiary, Sale of Stock [Line Items]
Issuance of common stock (shares)		3,450,000
Class A Common Stock | Underwriter's option | Subsequent event
Subsidiary, Sale of Stock [Line Items]
Issuance of common stock (shares)	1,196,562
Class B Common Stock
Subsidiary, Sale of Stock [Line Items]
Issuance of common stock (shares)			51,889,772
Common stock, shares outstanding	37,243,210			48,439,772	0
Class B Common Stock | Subsequent event
Subsidiary, Sale of Stock [Line Items]
Common stock, shares outstanding	37,243,210
Outstanding shares in class as a percent of the total shares outstanding	49.70%
Cactus LLC | Subsequent event
Subsidiary, Sale of Stock [Line Items]
Redeem CW Units from certain direct and indirect owners (in units)	11,196,562
Cactus LLC | Class B Common Stock
Subsidiary, Sale of Stock [Line Items]
Redeem CW Units from certain direct and indirect owners (in units)		3,450,000
CACTUS INC | Follow On Offering | Subsequent event | Maximum
Subsidiary, Sale of Stock [Line Items]
Debt Issuance Costs, Current, Net	$ 1.0